Getty JavaScript Class

Validating zip code

function isNum(passedVal) {
    if (passedVal == "") {
        return false
    }
    for (i=0; i<passedVal.length; i++) {
        if (passedVal.charAt(i) < "0") {
            return false
        }
        if (passedVal.charAt(i) > "9") {
            return false
        }
    }
    return true
}

function validZip(inZip) {
    if (inZip == "") {
        return true
    }
    if (isNum(inZip)) {
        return true
    }
    return false
}


if (form.zip.value == "" && form.dealerList.selectedIndex == -1) {
    alert("You must either enter a Zip code, or pick the dealer
    closest to you")
    form.zip.focus()
    return false
}

if (!validZip(form.zip.value)) {
    alert("That is an invalid Zip code")
    form.zip.focus()
    form.zip.select()
    return false
}